The present invention relates to a method of adjusting a bimetal trip element in an electric switching device with at least one bimetal strip securely fixed on one side, one tripping shaft to be pressurized by the unlatched end of the bimetal strip, as well as an adjusting screw.
Switching devices of this type are used particularly in low voltage applications and are well known in diverse designs. In addition to three-pole trip elements, such as those found in U.S. Pat. Nos. 3,162,739, 3,244,837 or 3,815,064, there are also monopole configurations for power circuit-breakers or similar small circuit-breakers. To adjust the bimetal trip element, it is customary to first set up the adjusting screw and then to perform a tripping test. This requires that the switching device, or at least the part of the switching device that contains the bimetal trip element, be connected to a test circuit. Depending on the result of the tripping test, the setting of the adjusting screw must then be corrected and another test is performed, after the bimetal strips have first cooled down to ambient temperature. Several tests might be necessary, depending on the desired or required accuracy of the adjustment. The time needed for such an adjustment is, therefore, considerable.